The invention relates to a device for preventive detection of faults in a load connected to an AC electrical power supply system by means of a first switch, a device comprising control means controlling the first switch, the control means comprising means for detecting the type of load and means for detecting a fault with test means to temporarily connect the load to test power supply means, and means for measuring the current in the load.
A known device (EP-A-581,078) comprises an optical circuit for detecting connection of a plug in a socket connected to the electrical mains power system. It then performs fault detection by measuring the current in the load when the latter is supplied under low power either by a pulse generator or by the mains power system via a step-down transformer. This document indicates that it is possible to detect the type of loads, more particularly the fact that the load is purely dissipative or not, from measurement of the current when the test power supply is constituted by a pulse generator. It does not however provide any details on how this detection is performed. In practice, the device described does not really enable recognition of the nature of the load and fault detection is not adapted to the type of load.